Data and/or graphic images are often placed on plastic cards, such as credit cards, identification cards and the like, by thermal printing. In thermal printing, which is inherently a contact form of printing, a printhead makes intimate contact with a ribbon and the card in order to print the desired data and/or graphic image(s) on the card.
Often times, a card may contain particulate contaminants on one, or both, of its generally planar side surfaces. These contaminants may be a result of the card production techniques, or improper care and storage of card stock. As a result, the card is often cleaned, prior to printing, in order to remove the contaminants. While cleaning the card removes loose contaminants, solidly affixed contaminants may remain. These remaining contaminants are a threat to the printhead because as the printhead makes contact with a contaminant during the printing operation on the card, the resistive elements on the printhead may be damaged, rendering portions of the printhead inoperable. Since printhead replacement is an expensive and time consuming operation, it would be desirable to prevent contact between a printhead and a card that has contaminants on its surfaces.